[V3, 2/2] mtd: brcmnand: Detect sticky ucorr ecc error on dma reads

[Kamal Dasu]

It's ok to fix it up.

Kamal

On Mon, Jul 11, 2016 at 2:49 AM, Boris Brezillon
<boris.brezillon at free-electrons.com> wrote:
> On Sun, 10 Jul 2016 22:04:52 -0700
> Brian Norris <computersforpeace at gmail.com> wrote:
>
>> Hi,
>>
>> Looking through Boris's pull request, I noticed an issue:
>>
>> On Thu, Jun 09, 2016 at 05:17:55PM -0400, Kamal Dasu wrote:
>> > This change provides a fix for controller bug where nand
>> > controller could have a possible sticky error after a PIO
>> > followed by a DMA read. The fix retries a read if we see
>> > a uncorr_ecc after read to detect such sticky errors.
>> > The fix applies to only controller version 7.0 and 7.1.
>> >
>> > Signed-off-by: Kamal Dasu <kdasu.kdev at gmail.com>
>> > ---
>> > V3 changes
>> >  none
>> > V2 Changes
>> >  Restrict controller bug workaround to version 7.0 and 7.1
>> > ---
>> >  drivers/mtd/nand/brcmnand/brcmnand.c | 18 ++++++++++++++++++
>> >  1 file changed, 18 insertions(+)
>> >
>> > diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
>> > index 7ee9617..1156495 100644
>> > --- a/drivers/mtd/nand/brcmnand/brcmnand.c
>> > +++ b/drivers/mtd/nand/brcmnand/brcmnand.c
>> > @@ -1602,9 +1602,11 @@ static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip,
>> >     struct brcmnand_controller *ctrl = host->ctrl;
>> >     u64 err_addr = 0;
>> >     int err;
>> > +   static bool retry = true;
>>
>> Is this intentionally static? That means your retry will only be
>> performed exactly once *ever*. Probably not what you expected?
>>
>> Boris, if this is indeed unintended, would you rather fix this up in the
>> original patch and send me a new pull request?
>
> I'll fix the initial commit and send a new PR once Kamal has confirmed
> this variable should not be static (which is also my opinion).
>
>> Or have my apply the
>> trivial fixup (i.e., s/static//) as a separate patch on top?
>
> Thanks,
>
> Boris



-- 
Kamal Dasu
Principal Engineer | Broadcom Ltd. 200 Brickstone Sq Andover | 978-719-1405